BIIB Congressional Stock Trades & Insider Buying (2026)

BIIB insider buying and selling over the past year

Over the past year BIOGEN INC. insiders filed 3 open-market Form 4 trades — 1 purchases worth $585 and 2 sales worth $665.7K — which makes them net sellers by $665.1K.

Most of the selling was pre-scheduled: 2 of the 2 sales (100.0%) were flagged as Rule 10b5-1 plan trades, which are set up in advance and say less about an insider's current view than discretionary sales. Activity clustered in 2026-02 (3 trades); the latest filing in this window is dated 2026-02-12. The average open-market sale price was $195.32; the last close of $232.65 is 19.1% above that level, so sellers left upside on the table. The single largest trade was a sale of 2,660 shares worth $531.5K on 2026-02-09. Since the most recent filing the stock has moved +19.0%, from $195.50. Insiders paid an average of $195.04 per share for their open-market purchases; against the last close of $232.65 that cost basis is sitting on a gain at +19.3%.

Where BIIB trades relative to its one-year range

BIOGEN INC. closed at $232.65 on 2026-10-16, inside a one-year range of $143.00 to $235.35. That puts the stock near the top of its range, at 97.1% of the distance from low to high. Over one year the share price moved +63.5%, and over roughly three months +12.9%. Average daily volume over the last month was about 1,294,768 shares.

Across 137 companies in the same SEC industry group (SIC 28) with a full year of prices in Gemral Edge, the median one-year return was +12.0%. BIIB is ahead of that median and beat 91% of that peer group on this measure.

Members of Congress who traded BIIB

STOCK Act disclosures show 28 trades in BIIB by 8 members of Congress over five years (15 purchases, 13 sales), most recently on 2026-09-24. The most active traders were Ro Khanna (D-CA), 13 trades; Maria Elvira Salazar (R-FL), 5 trades; Robert P. Bresnahan, Jr. (R-PA), 3 trades; Gilbert Ray Cisneros, Jr. (D-CA), 2 trades; Josh Gottheimer (D-NJ), 2 trades.

By party the trades split 18 by Democrats, 10 by Republicans; by chamber, 27 from the House, 1 from the Senate.

BIIB lobbying disclosures

BIOGEN INC. appears in 4 Lobbying Disclosure Act filings between 2018 and 2018, with $840.0K in reported lobbying spend.

Compare BIIB with indexed peers from the same industry group

These peers have full Gemral Edge dossiers and the closest one-year price move to BIIB:

• LLY one-year return +53.4%
• MRK one-year return +73.9%
• AMGN one-year return +46.2%
• REGN one-year return +38.9%
• BMY one-year return +37.7%

Sources and method

Every figure above is computed from public filings stored in Gemral Edge, not estimated. Insider figures count only open-market purchases and sales reported on SEC Form 4; option exercises, grants and gifts are excluded because they do not reflect a decision to buy or sell at market prices.

• SEC EDGAR Form 4 (edge_insider_trades, codes P/S open-market only) — as of 2026-02-12
• edge_prices_eod (end-of-day close) — as of 2026-10-16
• House PTR / Senate eFD disclosures (edge_congress_trades) — as of 2026-09-24
• Senate LDA filings (edge_lobbying_filings)

BIIB data questions

Are BIIB insiders buying or selling stock?

Over the past year BIOGEN INC. insiders filed 3 open-market Form 4 trades — 1 purchases worth $585 and 2 sales worth $665.7K — which makes them net sellers by $665.1K.

What is the one-year price range for BIIB?

Based on end-of-day closes through 2026-10-16, BIIB traded between $143.00 and $235.35, last closing at $232.65.

Has any member of Congress traded BIIB stock?

Yes. 8 members disclosed 28 trades in BIIB over five years; the most recent disclosed trade date is 2026-09-24.